public class digui2 {
    public static void main(String[] args) {
        int sum = jieceng(5);
        System.out.println(sum);

    }

    public static int jieceng(int i){
        int result = 1;
        if (i==0){
            result=result;
        }else {
            result=i*jieceng(i-1);
        }
        return result;
    }
}
